Une Moitié

Question

Est-ce-que une  moitié toujours feminine parce-que demi n'est pas,

Accepted Answer

Bonjour Gordon,
‘demi’ is either feminine or masculine depending on the expression it is used in.
half a [noun] = un/une demi-nom ('demi-' here is technically called a prefix and is part of the noun/expression and therefore doesn’t change)

une demi-bouteille (féminin) = half a bottle
un demi-seau d’eau (masculin) = half a bucket of water

[noun] and a half = [nom] et demi/demie ('demi(e)' here is like an adjective and it will agree in gender only with the noun it refers to)

une bouteille et demie (féminin) = a bottle and a half
un cahier et demi (masculin) = a notebook and a half

I hope this is helpful.
Bonne journée!